It is now conventional to reduce certain drugs to a dry or powdered form to increase the shelf life of drugs and reduce inventory space. Such dry or powdered drugs are generally stored in a sealed vial and reconstituted into liquid form for administration to a patient by adding a diluent or solvent. A conventional vial includes an open end, a rim surrounding the open end and a reduced diameter neck portion adjacent the rim. The vial is conventionally sealed with an elastomeric stopper which includes a portion inserted into the neck of the vial and a planar rim portion which overlies the vial rim. The stopper is normally secured to the vial rim with an aluminum collar or cap. The aluminum collar includes a tubular portion which surrounds the rim portions of the stopper and vial, an inwardly projecting annular portion which overlies the rim portion of the stopper and a distal portion which is crimped into the vial neck beneath the vial rim portion. Because aluminum is malleable, the collar accommodates the buildup of tolerances of the dimensions of the stopper and vial rim. The dimensions and tolerances of standard vials and stoppers are set by the International Standards Organization (ISO).
A powdered drug is generally reconstituted by inserting the needle of a syringe through the pierceable stopper on the vial and injecting a diluent, such as water, or a solvent into the vial. The reconstituted drug is then reaspirated from the vial with the same or a different syringe after mixing the diluent or solvent with the dry drug. As will be understood, this method exposes the healthcare worker to being pricked by the needle of the syringe and contamination of the needle or the drug.
The prior art has therefore proposed various fluid or liquid transfer assemblies which may be secured to a vial under sterile conditions and which may then utilized to transfer liquid, such as a diluent or solvent, from a syringe to a vial and reconstituted medicament from the vial to a syringe which prevent contamination of the liquid medicament. In the most preferred embodiments, the assembly is protected from contamination by a cap or cover which is removed only prior to use. In the embodiments disclosed in the prior art, the transfer assembly includes a needle which pierces the stopper of the vial and the liquid is transferred through the needle lumen as disclosed, for example, in U.S. Pat. No. 5,429,256. In other embodiments, the conventional vial stopper is eliminated in favor of a fluid transfer assembly having a rubber stopper which is inserted into the neck of the vial without a planar rim portion. The stopper remains within the vial until such time as reconstitution of the drug is required. When the transfer assembly is actuated, the stopper is urged toward the interior of the vial to open the neck, thereby permitting fluid flow through the transfer assembly into the vial body. Examples of such embodiments include the MONOVIAL.RTM. line of drug delivery devices manufactured and sold by Becton Dickinson Pharmaceutical Systems of Le Pont de Claix, France and exemplified by U.S. Pat. No. 5,358,501. Although this embodiment is an excellent drug reconstitution system having superior properties, particularly convenience of use and maintenance of the sterile conditions of the drug in the vial, particularly where the vial is of a relatively large size, typically twelve milliliters or more, pharmaceutical companies have expressed an interest in an approach where the vial may also be a smaller size.
The need therefore remains for a vial transferset which may be utilized with an ISO standard vial and stopper to transfer liquid from a conventional syringe to the vial or from a vial to a syringe after reconstituting a drug, for example, which is relatively simple in design and which reduces or eliminates contamination of the drug. It would also be desirable to eliminate the use of a conventional syringe needle to pierce the elastomeric stopper which seals the vial. As will be understood by those skilled in the art, a conventional syringe needle is thin and has an internal axial lumen or bore. The needle must therefore be withdrawn during aspiration of the vial or reaspiration where the medicament is reconstituted in the vial following delivery of a diluent or solvent to the vial. Where the needle is not substantially completely withdrawn during reaspiration of the vial, liquid medicament remains in the vial because the only liquid communication with the syringe is through the needle lumen. This may be a problem particularly where the vial is relatively small. For example, assuming a twenty millimeter long needle which pierces a two to three millimeter thick stopper, if the needle is pushed all the way through the stopper, there may be distance of as much as seventeen millimeters between the needle opening and the inner surface of the stopper. This amount below the needle lumen will not be reaspirated unless the needle is substantially withdrawn.
The vial transferset and method of this invention solves these problems by providing a relatively simple and efficient fluid transfer assembly which may be affixed to an ISO standard vial which assures complete reaspiration of the vial and which does not require accurate positioning of the needle during reaspiration.